1. Field
The following description relates generally to a driving apparatus of a display device and, more particularly, to a driving apparatus of an organic light emitting diode (OLED) display.
2. Description of the Related Art
A display device is a device in which a plurality of pixels are disposed in a matrix form to form a display panel, where scan lines and data lines are connected to the pixels, and data signals are selectively applied to the pixels to display images. The display device may be a passive matrix type of light emitting display device or an active matrix type of light emitting display device, according to how the pixels are driven. In terms of resolution, contrast, and operation speed, the active matrix type of light emitting display device, in which unit pixels are selectively lighted, is becoming more widely used.
Such display devices are used as monitors for devices such as personal computers, mobile phones, and mobile information terminals, such as personal digital assistants (PDAs) and various information devices. Liquid crystal displays (LCDs) using a liquid crystal panel, organic light emitting diode (OLED) displays, plasma display panels (PDPs) using a plasma panel, and the like, are examples of display devices. Recently, various light emitting display devices that are relatively light and small, when compared with cathode ray tubes (CRTs), are being developed, and in particular, the organic light emitting diode (OLED) display is receiving much attention, as it has good luminance efficiency, brightness, wide viewing angles, and fast response times.
One factor that is used for improving display quality of the OLED display is its gamma setting. Gamma setting refers to a correlation between display luminance and gray scale data, which is defined according to a gamma curve. In order for the OLED display to have or retain a stable display quality, a very accurate gamma setting is required. In the actual OLED display, a gamma setting error occurs occasionally due to various factors such as a standard deviation between components, a cell gap of a liquid crystal panel, a change in the thickness of color filters, a driving voltage, and various other factors. The error occurrence in the gamma setting causes a deviation between an actual display luminance and a display luminance according to gray scale data. Thus, in order to minimize or reduce such deviation, multi-time programming (MTP) is performed to program a reference gamma voltage in real time. The reference gamma voltage is a voltage inputted to a driving circuit that generates a data signal for determining a display luminance. The driving circuit generates a data signal by using the reference gamma voltage according to the gray scale data, and a light emitting element emits light according to the data signal. Thus, if the reference gamma voltage changes, the display luminance of the OLED display also changes. In this case, however, if a surge voltage, noise, or the like, is inputted to an MTP cell performing MTP, the programmed reference gamma voltage is altered or varied.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.